High Level Architecture

This article is about the IEEE standard for distributed simulation. For other uses, see High- and low-level.

The High Level Architecture (HLA) is a standard for distributed simulation, used when building a simulation for a larger purpose by combining (federating) several simulations.[1] The standard was developed in the 1990s under the leadership of the US Department of Defense[2] and was later transitioned to become an open international IEEE standard. It is a recommended standard within NATO through STANAG 4603.[3] Today the HLA is used in a number of domains including defense and security and civilian applications.

The purpose of HLA is to enable interoperability and reuse. Key properties of HLA are:

  • The ability to connect simulations running on different computers, locally or widely distributed, independent of their operating system and implementation language, into one Federation.
  • Ability to specify and use information exchange data models, Federation Object Models (FOMs), for different application domains.
  • Services for exchanging information using a publish-subscribe mechanism, based on the FOM, and with additional filtering options.
  • Services for coordinating logical (simulation) time and time-stamped data exchange.
  • Management services for inspecting and adjusting the state of a Federation.

HLA forms the basis for developing standardized and extendable FOMs in different communities, for example in aerospace and defense.

The architecture specifies the following components.

Components of an HLA federation
  • A Run-time Infrastructure (RTI) that provides a standardized set of services through different programming languages. These services include information exchange, synchronization and federation management
  • Federates that are individual simulation systems using RTI services.
  • A Federation Object Model (FOM) that specifies the Object Classes and Interaction Classes used to exchange data. The FOM can describe information for any domain.

Together the above components form a Federation.

The HLA standard consists of three parts:

  1. IEEE Std 1516-2010 Framework and Rules,[4] which specifies ten architectural rules that the components or the entire federation shall adhere to.
  2. IEEE Std 1516.1-2010 Federate Interface Specification,[5] which specifies the services that shall be provided by the RTI. The services are provided as C++ and Java APIs as well as Web Services.
  3. IEEE Std 1516.2-2010 Object Model Template Specification,[6] which specifies the format that HLA object models, such as the FOM, shall use.
  1. ^ Kuhl, Frederick; Weatherly, Richard; Dahmann, Judith (October 18, 1999). Creating Computer Simulation Systems: An Introduction to the High Level Architecture (1 ed.). Prentice Hall. ISBN 0130225118.
  2. ^ Dahmann, Judith (1997). "The Department of Defense High Level Architecture" (PDF). Proceedings of the 29th conference on Winter simulation - WSC '97. pp. 142–149. doi:10.1145/268437.268465. ISBN 078034278X. S2CID 6047580.
  3. ^ STANAG 4603: Modelling and Simulation Architecture Standards for Technical Interoperability: High Level Architecture (HLA). NATO.
  4. ^ IEEE Standard for Modeling and Simulation (M&S) High Level Architecture (HLA)— Framework and Rules. IEEE Computer Society. 18 August 2010. ISBN 978-0-7381-6251-5.
  5. ^ IEEE Standard for Modeling and Simulation (M&S) High Level Architecture (HLA)— Federate Interface Specification. IEEE Computer Society. 18 August 2010. ISBN 978-0-7381-6247-8.
  6. ^ IEEE Standard for Modeling and Simulation (M&S) High Level Architecture (HLA)— Object Model Template (OMT) Specification. IEEE Computer Society. 18 August 2010. ISBN 978-0-7381-6249-2. Archived from the original on August 18, 2019.